1. Field of the Invention
The present invention relates in general to a method and an apparatus for operating a microwave oven, and more particularly to a microwave oven and a method of controlling the operation thereof in which an algorithm is provided to virtually operate the microwave oven.
2. Description of the Related Art
Generally, microwave ovens utilize microwaves when cooking food. In other words, when the microwaves are applied to food, molecules in the food move, resulting in the generation of frictional heat. As a result, the food is heated by the frictional heat.
The microwaves are generated by a magnetron which performs an oscillating operation at a fundamental frequency of 2450 MHz.
FIG. 1 shows such a microwave oven performing a cooking operation by heating the food with the microwaves generated by the magnetron. As shown in this drawing, the microwave oven comprises a magnetron 36, an oscillator 37 connected to the magnetron 36 for oscillating the magnetron 36 at a desired frequency, a high-voltage transformer 38 connected to the magnetron 36 and the oscillator 37 for applying a high voltage to the magnetron 36, a lamp 33 for lighting the inside of a cooking chamber (not shown), a turntable motor 34 for rotating food (not shown) so that the food can evenly be cooked during the operation of the magnetron 36, a fan motor 35 for cooling the magnetron 36 and circulating air in the cooking chamber during the operation of the magnetron 36, a main relay 31 being turned on/off to control alternating current (referred to hereinafter as AC) power supply to the lamp 33, the turntable motor 34 and the fan motor 35, and a power relay 32 being turned on/off to control AC power supply to the magnetron 36.
The microwave oven further comprises an operating panel 13 and a display unit 11. As shown in FIG. 2, the operating panel 13 includes a plurality of key switches for inputting key signals regarding various functions desired by the user, such as cooking time, cooking menu, microwave oven output, cooking start and cooking stop. The display unit 11 is adapted to display the cooking function which the user selects through the operating panel 13 and the operating state of the microwave oven externally.
The microwave oven further comprises a control unit 20 for controlling the main relay 31 and the power relay 32 in response to the key signals inputted by the operating panel 13, to drive the magnetron 36 and the turntable motor 34. The control unit 20 also acts to display the inputted contents through the display unit 11.
The control unit 20 includes a microcontroller 25 for storing a program therein, an input buffer 23 for buffering the key signals inputted by the operating panel 13 and transferring the buffered signals to the microcontroller 25, a display driver 21 for driving the display unit 11 under the control of the microcontroller 25, and a load driver 27 for driving the main relay 31 and the power relay 32 under the control of the microcontroller 25.
The operation of the microwave oven with the above-mentioned construction will hereinafter be described.
First, the user positions the food on a turntable (not shown) and operates the key switches on the operating panel 13. Then, in response to the key signals inputted by the operating panel 13, the control unit 20 controls the main relay 31 and the power relay 32 to drive the turntable motor 34, the fan motor 35 and the magnetron 36.
As the power relay 32 is turned on, the high-voltage transformer 38 applies the high voltage to the magnetron 36, thereby causing the magnetron 36 to generate the microwaves. As a result, the food on the turntable is heated by the microwaves from the magnetron 36, while being rotated by the turntable motor 34. In this manner, the cooking operation of the microwave oven is performed.
At this time, the display unit 11 is driven by the display driver 21 under the control of the microcontroller 25 to display the cooking time, operating time, etc.
As mentioned above, the microwave oven is a kitchen utensil in which potentially dangerous microwaves are present and the accompanying heat is considerably high. Also, it is complex to operate the operating panel in the microwave oven. Further, the microwave oven has various functions. For this reason, it is necessary for the user to learn the operating method upon or after purchasing the microwave oven.
However, the user is liable to avoid testing the operation of the microwave oven due to the existence of potentially dangerous microwaves. In this connection, it is difficult for the user to learn the operating method of the microwave oven.
The user must wait for an amount of time equal to the actual cooking time even though they are only testing the operation of the microwave oven. Furthermore, the user has the trouble of putting food or water into the microwave oven to avoid overheating the microwave oven during the operation test.